Method and apparatus for creating a modified tissue graft

ABSTRACT

A method and apparatus is provided for creating a modified tissue graft, wherein an anatomical site at which the modified tissue graft is to be placed is identified, desired characteristics for the modified tissue graft are identified based at least upon the anatomical site, one or more types of graft modifications and regions of the tissue graft to be modified are identified to achieve the desired characteristics; and at least a first area and a second area of the exterior surface of the tissue graft are modified by compressing, cutting and/or removing one or more portions thereof to create first designed surface features which cause the tissue graft to have first characteristics in the first area and second designed surface features which cause the tissue graft to have second characteristics in the second area.

RELATED APPLICATION DATA

This application claims priority to U.S. Provisional Application Ser.No. 62/805,032, filed Feb. 13, 2019, and is a continuation-in-part ofU.S. application Ser. No. 16/410,167, filed May 13, 2019, which is acontinuation of U.S. application Ser. No. 15/487,585, filed Apr. 14,2017, now U.S. Pat. No. 10,285,795, which is a continuation of U.S.application Ser. No. 14/678,188, filed Apr. 3, 2015, now U.S. Pat. No.9,622,845, which is a continuation-in-part of U.S. application Ser. No.13/687,082, filed Nov. 28, 2012, now U.S. Pat. No. 9,050,177, issuedJun. 9, 2015, which is a continuation of U.S. patent application Ser.No. 13/101,022, filed May 4, 2011, now U.S. Pat. No. 8,858,647, issuedOct. 14, 2014, and claims priority to U.S. Provisional Application Ser.No. 61/331,805, filed May 5, 2010; the contents of said earlierapplications are incorporated by reference in their entirety herein.

FIELD OF THE INVENTION

The present invention relates to tissue grafts with resurfacing in atargeted methodology based on anatomic location and medical functionalindications.

BACKGROUND OF THE INVENTION

Current surgical reconstruction of external tissue defects utilizes asolid, porous sheet with or without perforations. Current grafts allowfor perforations that do enhance fluid egress and in growth of newtissue but due to the constrictive nature of such tissue grafts, theincidences of recurrences and the inability to expand with theapplication of increased pressure has allowed for a significantincidence of recurrence, stress tears, and an inability for expansionused in reconstructive and aesthetic procedures. Current tissue graftsalso do not allow for the ability to enhance the graft as it is placedbetween specific anatomic points. The current novel invention appliesthese engineering applications to achieve targeted resurfacing withsurgical tissue grafts. None of the references below discuss theadvantages of utilizing the current method and apparatus of applyingdesigns and templates to external surgical tissue grafts.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of a tissue graft having various surface patternsin accordance with an embodiment of the invention, which patterns may beused to contain or retain medicants, tissues or other materials inaccordance with other embodiments of the invention;

FIGS. 2A and 2B illustrate configurations of die cuts made to alter atissue graft in accordance with embodiments of the invention;

FIGS. 3A and 3B illustrate a top and bottom, respectively, of a tissuegraft having patterns in accordance with the invention;

FIGS. 3C, 3D, 3E and 3F illustrate tissue grafts modified to havedifferent areas with different surface patterns in accordance withembodiments of the invention;

FIG. 4 is a flow diagram illustrating a process in accordance with theinvention;

FIG. 5 is a table which illustrates aspects of targeted resurfacing inaccordance with an embodiment of the invention;

FIGS. 6A, 6B, and 6C illustrate a method of modifying a tissue graftwith a template to create a modified tissue graft having one or moresurface patterns and associating one or more medicants with said surfacepatterns in accordance with an embodiment of the invention; and

FIGS. 6D and 6E illustrate additional embodiments of a modified tissuegraft in accordance with the invention.

SUMMARY OF THE INVENTION

Various methods and apparatus for creating a modified tissue graft, andmost preferably, an external tissue graft, are disclosed. Aspects of theinvention comprise: 1) a method for the creation of templates used tocreate a multitude of patterns in a variety of modified tissue grafts;2) an apparatus that through either cutting, compression and/or removalof segments of tissue create the modified tissue graft; 3) an apparatusthat through either cutting, compression and/or removal of segments of apreformed template (such as made of synthetics and or metal) thatmirrors a template that can be used as a tissue graft, such as anexternal graft; and/or 4) a method of measuring, through softwareanalysis and an apparatus, the physical properties of the tissue graftand its pre and post-operative properties and appearance, such as foruse in modifying a tissue graft to create a modified tissue graft.

Additional aspects of the invention comprise modified tissue grafts andmethods of creating a modified tissue graft by modifying a tissue graft,such as by one or more templates that cut, compress and/or remove areasof the initial tissue graft.

In one embodiment, a template is used to modify the surface of a tissuegraft to include variable and multiple patterns, creating a modifiedgraft which is configured for incorporation into a particular anatomicarea.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, allowing for faster wound healing by promotingvascular ingrowth of the body's tissue in specific areas due to targetedresurfacing of the modified tissue graft.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, allowing for reduced scaring by decreasingingrowth of the body's tissue in specific areas due to targetedresurfacing of the modified tissue graft.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, reducing stress in grafts subject to continuousmotion, such as, in the knee, hip, and cervical region due to targetedresurfacing.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, reducing stress in grafts subject to increasedpressure gradients such as in the abdominal wall, inguinal hernia, andarterial grafts.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, allowing for selective expandability (such asvia partial or non-through expansion incisions and/or through expansionincisions of various thicknesses in the graft) in order to achievebetter contour and external appearance due to targeted resurfacing.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, allowing for selective expandability (such asvia partial or non-through expansion incisions and/or through expansionincisions of various thicknesses in the graft) in order to achievebetter outflow of blood in venous grafts due to targeted resurfacing.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, allowing for selective traction or adhesionpoints of tissue grafts to key anatomic areas when needed in order toincrease fixation at insertions and origins to reduce slippage due totargeted resurfacing of the graft.

In one embodiment, the invention is configured to, and an advantage ofthe invention comprises, allowing for an increase in the period of timeof utilization and longevity of the modified tissue graft.

Another embodiment of the invention comprises methods and apparatus forcreating a graft, such as a tissue graft, which includes a medicant,such as antibiotics, growth factors, or chemotherapeutics, or othertissues, such as stem cells due to targeted resurfacing.

In one embodiment, modifications are made to an initial tissue graft tocreate a modified tissue graft having certain characteristics orproperties. The particular modifications and the areas where themodifications are made may be selected to achieve particularcharacteristics or properties in different areas of the modified tissuegraft, such as based upon the desired use, including the particularanatomical location at which the modified tissue graft is to be used, aswell as the functional purpose the modified tissue graft is to serve.

Further objects, features, and advantages of the present invention overthe prior art will become apparent from the detailed description of thedrawings which follows, when considered with the attached figures.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the invention comprise methods of modifying a tissue graft tocreate a modified tissue graft, which tissue graft may have featureswhich are selected to address particular objectives relative to aparticular anatomical site; modified grafts, including modified tissuegrafts which have features which are designed for particular medicalindications and/or for a particular anatomical site; and methods ofmaking one or more templates which are usable to modify a tissue graftto create a modified tissue graft, such as by cutting or removingportions of the tissue graft or otherwise create surface patterns orother features.

One embodiment of the invention is a tissue graft having features whichare selected or designed to address particular objectives, such asrelative to a particular anatomical site, medical condition or the like.In a preferred embodiment, the tissue grafts are modified tissuegrafts—e.g. an initial tissue graft which does not have all of thedesired features or characteristics which is then modified or altered tocreate a modified tissue graft which has desired features orcharacteristics.

In one embodiment of the invention, the tissue grafts comprise cadaverichuman tissue, or may comprise amniotic or chorionic tissue (includinggenetically altered human de-cellular amniotic and/or chorionic tissue),or other tissue In other embodiments, the tissue grafts may comprisecellular non-human tissue, including cellular and acellular processedgrafts. The tissue grafts may also comprise synthetic materials. Asindicated, in one embodiment, such a tissue graft is modified inaccordance with the invention to create a modified graft.

As detailed herein, in various embodiments of the invention, tissuegrafts are modified by cutting the grafts, removing material from thegrafts, compressing one or more areas of the graft or otherwise alteringthe surface(s) of the graft to create a modified tissue graft. Suchmodifications may, as detailed below, be accomplished in variousmanners, including via the use of templates such as dies or the like,which may be used to create such modifications.

FIG. 1 illustrates a tissue graft 20 in accordance with an embodiment ofthe invention. In accordance with the invention, the tissue graft 20comprises a modified tissue graft where cutting, compression and/orremoval of segments of graft material (such as spaced or separated byvarious distances between them) creates recessed expansion patterns(including slots, slits, depressions or openings) of various depths andshapes 22, adhesion projections of various heights and shapes 24, andthrough holes or openings 26 (including where the shape, location and/ororientation of the feature(s) is selected to achieve certaincharacteristics, such as expansion in certain directions, stressreduction in certain directions, etc.).

FIGS. 2A and 2B illustrate additional examples of tissue grafts 20 whichhave been modified in particular exemplary manners. In FIG. 2A, thetissue graft 20 has been modified to include a plurality of cuts orslits 30 one or more portions of a surface thereof, such as a topsurface. In the configuration which is illustrated, the cuts 30 are rowsof offset cut segments which are aligned with one another. Such aconfiguration may be referred to as “linear” modification. Thisconfiguration might be achieved, for example, using a die having aplurality of blades which, when pressed into a tissue graft, form amodified tissue graft having the cuts or slits 30 as illustrated.

In FIG. 2B, a tissue graft 20 has been modified to include a pattern orcuts or slits 30 in one or more portions of a surface thereof, such as atop surface. In the configuration which is illustrated, the cuts 30various of the cuts extend generally perpendicular to one another, andsome of the cuts intersect, while others do not. Such a configurationmay be referred to as “interval” modification. This configuration mightbe achieved, for example, using a die having a plurality of bladeswhich, when pressed into a tissue graft, form a modified tissue grafthaving the cuts or slits 30 as illustrated.

As is described in more detail below, these modifications may havevarious configurations and locations, including only being locatedacross the entire surface of the graft, or only in one or more areas ordiffering from area to area, and being on one side or both, such asdepending upon the desired characteristics of the graft. It has beenfound, for example, that the “linear” modification illustrated in FIG.2A results in the graft (or area thereof) having the characteristics ofbeing expandable (particularly in a direction transverse to thedirection of the cuts). On the other hand, the “interval” modificationillustrated in FIG. 2B results in graft (or area thereof) havingadhesion characteristics.

It will also be appreciated that the amount of modification to thegraft, or an area thereof, may be used to control the characteristics ofthe modified graft. For example, relative to the example in FIG. 2B, agreater number of cuts 30 may be used when a high adhesioncharacteristic is desired, while a pattern of fewer cuts 30 might beused when a lower adhesion characteristic is desired.

As noted, different types of modifications might be made, including todifferent areas of a graft, to achieve modified tissue grafts withdifferent characteristics. FIGS. 3A and 3B illustrate one example ofpatterns of adhesion features 22 and expansion features 24 relative to atop (in FIG. 3A) and bottom (in FIG. 3B) of a tissue graft 20, whichpatterns may be used to generate a tissue graft having particulardesired characteristics for a particular application, such as describedin more detail below relative to FIGS. 4 and 5 below.

The features of the tissue grafts may vary both in the nature of themodifications and the characteristics of the graft achieved thereby, notlimited to the following: (1) the modifications (such as createdpatterns or features, such as cuts, voids, etc.) may vary by thedistance between them and the modifications can be of various shapes,widths, thicknesses, and variegations; (2) the designated modificationsor other features can be either full thickness or partial thickness ofthe graft; (3) the designated modifications can be on both anterior andposterior surfaces of the graft; (4) the designated modifications may beconfigured to provide enhanced controlled expansion of the tissue graft;(5) the designated modifications may be configured to provide enhancedstress relief during motion of the tissue graft; (6) the designatedmodifications may be configured to provide enhanced adhesion between thetissue graft and anatomic region; (7) the designated modifications maybe configured to provide enhanced retention of various medicants andmaterials both in vitro and in vivo; and/or (8) the designatedmodifications may be configured to provide enhanced longevity andutilization of the graft.

As described in more detail below, aspects of the present inventioncomprise modified tissue grafts and methods of making the same so thatthe modified tissue graft has particular characteristics for addressingparticular anatomical regions/issues and medical conditions. Suchcharacteristics may comprise one or more of enhanced expansion,flexibility and/or stretch (such as when the tissue graft is to bewrapped about or around an anatomical area or part), traction, glide,adhesion, to reduce stress, such as shear forces, interaction ofcritical cells (between the graft and site tissue, such as increasingthe depth and speed of penetration of the site tissue into the graft) orperiod of utilization in anatomic areas where it is placed. For example,in one embodiment, modified tissue grafts are configured to facilitatefor faster wound healing by promoting vascular ingrowth of the body'stissue in specific areas due to targeted resurfacing of the modifiedtissue graft. As another example, in one embodiment, modified tissuegrafts are configured to facilitate reduced scaring by decreasingingrowth of the body's tissue in specific areas due to targetedresurfacing of the modified tissue graft. As illustrated in FIGS. 3A and3B, different areas of a tissue graft may be modified in differentmanners to create a modified tissue graft having areas with differentfeatures or characteristics (which may be referred to as “targetedresurfacing”). For example, as illustrated in FIG. 3C, one or moretemplates might be utilized to modify the end regions 21A,B of a tissuegraft 20 (but not a middle section 21C thereof) to create a modifiedtissue graft having features 25 with characteristics that increasetraction at the ends 21A,B (such as by having surface features which arerough and promote adhesion) and which promotes glide in the middle 21C(such as by having a surface in the middle which is generally smooth).Such a modified tissue graft might, for example, have advantages whenplaced at a particular anatomical region such as a knee joint.

As another example and illustrated in FIG. 3D, one or more templatesmight be utilized to modify the corner regions 21D-G (but not the middleof) a tissue graft 20. The resultant modified tissue grant may thusinclude tissue modification features 25 at the corners 21D-G that havecharacteristics that are configured to reduce mechanical sheer forceswhich are applied to the modified graft, such as to reduce scar tissueformation.

As yet another example as illustrated in FIG. 3E, one or more templatesmight be utilized to modify a midline portion 21H of a tissue graft 20.The resultant modified tissue graft might then have tissue modificationfeatures 25 along that centerline that have characteristics whichfacilitate wrapping of the modified tissue graft around an object, suchas an anastomosis.

It will thus be appreciated that one or more templates may be utilizedto modify a tissue graft in different areas in different ways. Asillustrated in FIG. 3F, the tissue graft 20 might be modified in a firstarea A in a first manner and a second area B in a second manner, thuscreating a modified tissue graft which is modified in different ways indifferent areas. Such modification may result in the modified tissuegraft having different characteristics in the different areas. Thedifferent characteristics and areas may correspond to different goals,features or characteristics of an anatomical area, including featuresrelating to the anatomy itself and/or a medicant condition which isbeing treated.

As indicated above, one or more templates might modify the differentareas of the tissue graft in different ways (remove areas of material,through-holes, etc.) to create a modified tissue graft having areas ofdifferent desired characteristics (adhesion, glide, traction, stressreduction, etc.). Of course, a single tissue graft might be modified inthe same or different way in a plurality of areas such as illustrated inFIG. 1F relative to similar areas A1 and A2 (e.g. two areas modified toenhance traction, three areas to increase expansion, etc.). Further, insome cases the different areas (and thus surface modifications) mayoverlap or transition, such as illustrated relative to areas C1 and C2in FIG. 3F. Also, as indicated above in FIGS. 3A and 3B, the opposingsides of the tissue graft may be modified or altered in the same orentirely different ways (or only one side might be modified and not theother), depending upon the application.

FIG. 4 is a flow diagram illustrating one embodiment of the inventioncomprising a process for creating a modified tissue graft. In oneembodiment, in a step S100, an anatomical region where a graft is to beplaced is identified. This may comprise, for example, anatomical regionwhere a wound, injury or the like exists. Of course, such a region maybe identified in various manners, such as by examination, machine scans,etc.

In a step S102, desired characteristics for the graft are identified,such as based upon the anatomical region, characteristics of the injuryor wound or the like. Such characteristics might comprise, but are notlimited to stress reduction, glide, adhesion, traction, scar reduction,osseous healing and/or integration, disease control, increased rate ofhealing, etc.

In a step S103, one or more types of graft modifications are identified,along with regions of the graft to be modified, to achieve the desiredcharacteristics. As indicated herein, the graft modifications mightcomprise one or more of forming cuts, pockets, folds, voids, slots,slits, or other modifications or changes to the graft. Further, theregions might comprise the front and/or back of the graft, or anyportions thereof.

In a step S104, the graft is modified to create a modified graft. Thisstep might comprise a step S104A in which one or more dies or templatesare obtained or created, such as described herein, which may be used tocreate the desired graft modifications. Then in a step S104B, the one ormore dies or templates may be used to modify the graft, such as bycutting the graft, removing material from the graft, compressing areasof the graft, etc., as described herein.

FIG. 5 illustrates examples of the invention, such as based upon theprocess just described. As illustrated, in an Example A, a patient mayhave an injury to a knee or shoulder which requires one or more grafts.The identified anatomical condition may thus comprise the knee orshoulder. The desired characteristic for the modified graft may be thatit stabilizes motion, by adhering at either or both ends of insertionand gliding in the middle. It may thus be desired to leave the middle ofthe graft smooth (for gliding purposes) but to modify the ends of thegraft so that they have adhesion characteristics, such as by heavilyresurfacing the ends thereof. One or more dies may then be used toresurface the ends of the graft to create a modified graft asillustrated, such as where the one or more dies are used to create cutsor slits in multiple directions, such as illustrated in FIG. 2B.

As illustrated by the other examples in FIG. 5 , in order to achievedesired characteristics, different areas of a graft may be modified indifferent manners, including by the level of modification. For example,as illustrated in Example D, a graft might be modified across its entiresurface, but the level of modification might vary in different areas,such as by having ends of the graft heavily modified (such as by a highfrequency of interval and/or linear cuts) and by having a middle sectionless heavily modified (such as by low frequency of interval and/orlinear cuts).

Further, as indicated in Example C, the front and back of a graft mightbe modified in different manners to achieve different characteristics oneach side of the graft.

Current medical devices are not applicable for creating the multitude ofdesired modifications to grafts for each use (such as varying dependingupon anatomical site, medical condition, etc.). In accordance with theinvention, an apparatus can be used to create the modificationsapplicable to a specific placement, whether pre- or intra-operatively.In some embodiments, a modified tissue graft may be pre-constructed andthen delivered to a hospital or doctor for use (thus eliminating theneed for construction of the modified tissue graft at the time of thesurgery), while in other embodiments, a modified tissue graft might bedesigned/created intra-operatively.

For example, measuring, such as through image capture and softwareanalysis, the physical properties of the anatomical site and/or thereconstructive tissue graft and its pre- and post-operative appearancemay be utilized to correlate the physical properties of a createdmodified graft to the site. In this regard, one embodiment of theinvention comprises a method of creating templates or other devices tomodify a tissue graft, such as to create a multitude of patterns intissue grafts. Such may consist of pre- or intra-operatively madetemplates.

In one embodiment, the templates may be based on an analysis of aparticular anatomical region, such as software analysis of an image ofinitial tissue defect, the template designed to allow for a desiredgraft pattern to reduce the potential pressure, reduce stress, decreasewear and tear, provide traction, or achieve other objectives whenimplanted or placed at a particular anatomical site. Based on factorssuch as, but not limited to, the size, shape, thickness, width,variegations, type, and the desired surgical outcome, a tissue graft maybe modified to include a pattern or other features. Due to thevariability in a defect being reconstructed, such as the abdominal wall,breast, face, and extremities, different template patterns may begenerated. Software analysis may be used to create an appropriate xtissue graft for an identified existing defect.

In one embodiment, different materials may be used to make the templatesand their respective patterns. In a preferred embodiment of theinvention, modified grafts may be created which not only permit meshexpansion, but provide for a multitude of various designs, shapes,patterns, variegations and materials to accommodate the existing defectto achieve the desired reconstructive and aesthetic results.

In one embodiment, software and/or hardware may be used to perform apre- manufacture or pre-operative analysis. Templates may be constructedfrom a pre-made mold, and be made of different materials such as metalor plastic to be integrated with a compression device. The template canbe integrated with a stationary or portable compression apparatus thatcan create prepackaged tissue grafts in a pre-manufactured configurationby a manufacturer or to be subsequently sterilized and used by a surgeonin the operating room. A primary objective of the invention allows for atissue graft to be modified to create a tissue graft which is patternedto address or accommodate anticipated problems due to any and allactivity and reconstructive and aesthetic results.

In one embodiment, an apparatus, either via cutting, compression and/orremoval of segments of tissue (such as by pressing a template, such as adie, into contact with and/or into the surface of the tissue graft),creates a modified tissue graft for reconstruction by creating a desiredpattern within a graft. Compression can be used against the templatethat in turn creates the desired pattern.

While in certain embodiments templates, including dies, punches and thelike may be used to modify a tissue graft, other apparatus may be used.For example, lasers, water knives or the like may be used to modify thetissue grafts.

The templates or other apparatus which are used to modify a tissue graftto create a modified tissue graft may be made of a variety of materials,including synthetics, plastic, and metals; the templates or otherapparatus may be used in a manufacturing facility or operating room; thetemplates or other apparatus may be operable by manual pressure, airpressure, hydraulic pressure, or electrically driven apparatus such asmotor driven presses or screws, including via a portable compressiondevice.

As indicated herein, the reconstructive graft may include varioussurface or other features, including for enhancing the retention ofmedicants or other materials (unless otherwise indicated, the term“medicants” as used herein may include medicants, tissues or othermaterials, as described below). In one embodiment, for example, surfacefeatures such as projections, channels, depressions, voids, pockets orthe like may be formed in or through the tissue graft for accepting oneor more medicants (including but not limited to chemotherapeutics,antibiotics, growth factors or other drugs), other tissues (includinghuman non-human tissue, synthetic tissue, stems cells or the like) orother materials such as rebar (or other supportive or strengtheningmaterials). In one embodiment, the modified tissue graft may bepre-created with such features and then the medicants, other tissues ormaterials may be associated with the reconstructive tissue graft at alater time, such as before or during surgery. In other embodiments, amodified tissue graft may have such materials pre-associated. Forexample, a tissue graft may be modified by forming one or more pockets,sleeves, folds, voids or the like, and one or more medicants, tissues orother materials may be associated with those pockets or voids duringmanufacture. The pre-configured, pre-medicated reconstructive tissuegraft may then be provided to the surgeon for use. It will beappreciated that while medicants may be associated with a modifiedtissue graft, other materials might also be associated, such as othertypes of tissue (as described above), bone material, or even metalmeshes, or a variety of other materials (such as depending upon theparticular anatomical region and/or condition for which the modifiedtissue graft is intended).

The templates of the invention and/or other apparatus may be used toplace such medicants or other materials. For example, one template maybe used to modify the tissue graft, such as by creating the surfacepatterns, while other apparatus or devices may be used to associate themedicants or other materials (such as a medicant implanter, etc). Inother embodiments, these functions may be combined (such as by havingthe template modify the graft and place the medicants or other materialsor facilitate their placement by associated apparatus).

For example, FIG. 6A illustrates use of a template 120 to modify atissue graft 122, such as by using the template 120 to cut or removeportions of a surface of the graft 122. As illustrated in FIG. 6B, thetemplate 120 or another device may be used to associate a medicant 124(or other material such as tissue, as described above) with one or moreof the created surface features. FIG. 6C illustrates one embodiment of amodified graft 122 which includes one or more surface features and anassociated medicant 124. This pre-prepared modified graft 122 may thenbe located in a particular anatomical area of a patient.

As indicated, the template 120 may have various configurations andconstructions. For example, the template 120 might have the form of apunch. In other embodiments, the template 120 might have the form of oneor more dies, such as cutting dies. In some embodiments, more than onetemplate 120 might be used, such as by applying a first template in oneor more first areas and a second template in one or more second areas,or applying a first template to a first area and then a second templateto the same area.

FIG. 6D illustrates another embodiment of a modified graft 222 inaccordance with the invention. As illustrated, the modified graft 222may include one or more surface modifications, such as slots 230 whichfacilitate controlled expansion of the modified graft, such as describedabove. The modified graft 222 might, in addition or alternatively,include one or more features 232 which retain medicants. In oneembodiment, the medicant retaining features are configured toevenly/spatially distribute the associated medicants. As illustrated,this may be accomplished by evenly distributed medicant retainingfeatures. However, as one aspect of the invention, the medicantretaining features may have varying sizes or locations which areconfigured to cause associated medicants to be distributed in othercontrolled fashions (such as accounting for factors such as theconfiguration of the modified tissue graft, including varying thicknessthereof, and anatomical features where the graft is to be placed, suchas higher or lower blood flow in regions adjacent to the graft whenimplanted).

FIG. 6E illustrates different medicant retaining features. As oneexample, a medicant retaining feature may comprise or include a void,such as a bulbous cavity 300 formed in the tissue graft. As anotherexample, the feature might comprise a void or cavity which includes avalve 302. The valve 302 may be used to retain the medicants in thegraft during placement and/or control the flow or release of medicant orother materials from the associated cavity to the exterior of thegraft). The valve 302 might, for example, be formed of a portion of thetissue graft itself, such as an upper layer of the tissue graft which isperforated or slit. As yet another example, the feature might comprise apunch-type feature 304 which includes one or more voids, cavities,pockets or the like which can be used to retain medicants. Of course, asindicated herein, the size and shape of the medicant retaining featuresmay vary.

In one embodiment, the medicant retaining feature is intended to retainone or more medicants (or other materials, as described herein) forrelease once the tissue graft is located at the desired anatomical site.In other embodiments, the retaining feature might retain the medicant orother material once the graft is placed. For example, a synthetic meshmaterial which is located in the graft may remain in the graft after itis placed, thus strengthening the graft and/or the integration of thegraft with the anatomical site.

The medicant retaining feature may be used as part of other aspects ofthe invention, such as the targeted resurfacing feature described aboverelative to FIG. 4 . Referring to Example F, a center or middle sectionof a graft might be modified, such as by interval and/or linearmodification, to create an adhesion characteristic. This same region maybe modified to include one or more pockets, voids or other medicantretaining features with which one or medications (such as cancertreating pellets) might be associated. The ends of the graft may theneither not be modified or might be modified in other manners.

Example G in FIG. 4 illustrates another configuration in which amodified graft is configured to be used in an area infection. The graftmay be modified to have an adhering characteristic and include medicantretaining features with associated medicant for treating the infection.In this manner, the adhesion characteristic aids in maintaining thegraft in position at the treatment site and the medicant is thenreleased and absorbed at the site.

In this regard, it will be appreciated the type and nature of the graftmodifications may vary and be wide ranging, such as based upon theanatomical area and desired characteristics. Further, the modifiedtissue grafts may be utilized in a variety of anatomical locations. Inone preferred embodiment, the modified tissue grafts are external tissuegrafts (e.g. used in an external location). In such a configuration, theexternal tissue grafts may be particularly configured tofacilitate/expedite wound healing with minimal scarring.

The above description represents one embodiment of the presentinvention. However, many variations to the method and apparatus arepossible without deviating from the scope of the invention. It will beunderstood that the above described arrangements of apparatus and themethod described herein are merely illustrative of applications of theprinciples of this invention and many other embodiments andmodifications may be made without departing from the spirit and scope ofthe invention as defined in the claims.

What is claimed is:
 1. A method of creating a modified tissue graft forconnection at an anatomical site of a human body, comprising the stepsof: (a) obtaining a tissue graft from a location different than saidanatomical site, said tissue graft having an exterior surface; (b)identifying said anatomical site at which said modified tissue graft isto be placed; (c) identifying desired characteristics for said modifiedtissue graft, based at least upon the anatomical site; (d) identify oneor more types of graft modifications and regions of said tissue graft tobe modified, to achieve the desired characteristics; and (e) targetresurfacing said tissue graft by using at least one template to modifyat least a first area of said exterior surface of said tissue graft bycompressing, cutting and/or removing one or more portions of saidexterior surface of said tissue graft to create one or more firstdesigned surface features which cause said modified tissue graft to havefirst characteristics in said first area and to modify at least a secondarea of said exterior surface of said tissue graft by compressing,cutting and/or removing one or more portions of said exterior surface ofsaid tissue graft to create one or more second designed surface featureswhich cause said tissue graft to have second characteristics in saidsecond area.
 2. The method in accordance with claim 1 wherein saidmodified tissue graft is an external tissue graft.
 3. The method inaccordance with claim 2, wherein at least one of said first and seconddesigned surface features are configured to promote wound healing. 4.The method in accordance with claim 2, wherein at least one of saidfirst and second designed surface features are configured to reducescarring.
 5. The method in accordance with claim 1, further comprisingassociating one or more medicants with at least one of said first andsecond designed surface features.
 6. The method in accordance with claim5, wherein said one or more medicants comprise at least one of: anantibiotic, a growth factor, and a chemotherapeutic.
 7. The method inaccordance with claim 1, wherein said step of identifying desiredcharacteristics is further based upon characteristics of an injury orwound at said anatomical site.
 8. The method in accordance with claim 1,wherein said desired characteristics comprise one or more of: stressreduction, glide, adhesion, traction, scar reduction, osseous healingand/or integration, disease control and increased rate of healing. 9.The method in accordance with claim 1, wherein said first and seconddesigned surface features comprise one or more of: a cut, a pocket, afold, a void, a slot, and a slit.
 10. The method in accordance withclaim 1, wherein said first area comprises a first side of said tissuegraft and said second area comprises a second side of said tissue graft.11. The method in accordance with claim 1, wherein said first areacomprises a first end of said tissue graft and said second areacomprises a second end of said tissue graft.
 12. The method m accordancewith claim 1, wherein said at least one template comprises a die. 13.The method in accordance with claim 12, wherein said die comprises oneor more cutting elements.
 14. The method in accordance with claim 13,wherein said step of using said at least one template comprises pressingsaid die into said exterior surface of said tissue graft.
 15. The methodin accordance with claim 1, wherein said tissue graft comprises humancadaveric tissue.
 16. The method in accordance with claim 1, whereinsaid tissue graft compnses amniotic and/or chorionic tissue.
 17. Themethod in accordance with claim 16 wherein said amniotic and/orchorionic tissue comprises genetically altered human de-cellularamniotic and/or chorionic tissue.